Faraday rotator mirror FRM
FRM (Faraday rotator mirror) is used to change the polarization state of the input light, making the polarized light passing by the Faraday rotator and the mirror rotate 90 degrees in the direction of the input polarized light, orthogonal and vertical, and the polarization direction is opposite.

The working principle of Faraday rotator mirror is as follows: the input light is emitted from the fiber and converted into parallel light by the collimator. After rotating the polarization direction of the light by 45° through the Faraday rotator, it is reflected by the mirror and rotated again by 45° through the Faraday rotator. In this way, the polarization direction is rotated by 90° and finally output to the fiber through the collimator coupling.